hid-wiimote-debug.c

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/*
 * Debug support for HID Nintendo Wiimote devices
 * Copyright (c) 2011 David Herrmann
 */

/*
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the Free
 * Software Foundation; either version 2 of the License, or (at your option)
 * any later version.
 */

#include <linux/debugfs.h>
#include <linux/module.h>
#include <linux/seq_file.h>
#include <linux/spinlock.h>
#include <linux/uaccess.h>
#include "hid-wiimote.h"

struct wiimote_debug {
    struct wiimote_data *wdata;
    struct dentry *eeprom;
    struct dentry *drm;
};

static ssize_t wiidebug_eeprom_read(struct file *f, char __user *u, size_t s,
                                loff_t *off)
{
    struct wiimote_debug *dbg = f->private_data;
    struct wiimote_data *wdata = dbg->wdata;
    unsigned long flags;
    ssize_t ret;
    char buf[16];
    __u16 size;

    if (s == 0)
        return -EINVAL;
    if (*off > 0xffffff)
        return 0;
    if (s > 16)
        s = 16;

    ret = wiimote_cmd_acquire(wdata);
    if (ret)
        return ret;

    spin_lock_irqsave(&wdata->state.lock, flags);
    wdata->state.cmd_read_size = s;
    wdata->state.cmd_read_buf = buf;
    wiimote_cmd_set(wdata, WIIPROTO_REQ_RMEM, *off & 0xffff);
    wiiproto_req_reeprom(wdata, *off, s);
    spin_unlock_irqrestore(&wdata->state.lock, flags);

    ret = wiimote_cmd_wait(wdata);
    if (!ret)
        size = wdata->state.cmd_read_size;

    spin_lock_irqsave(&wdata->state.lock, flags);
    wdata->state.cmd_read_buf = NULL;
    spin_unlock_irqrestore(&wdata->state.lock, flags);

    wiimote_cmd_release(wdata);

    if (ret)
        return ret;
    else if (size == 0)
        return -EIO;

    if (copy_to_user(u, buf, size))
        return -EFAULT;

    *off += size;
    ret = size;

    return ret;
}

static const struct file_operations wiidebug_eeprom_fops = {
    .owner = THIS_MODULE,
    .open = simple_open,
    .read = wiidebug_eeprom_read,
    .llseek = generic_file_llseek,
};

static const char *wiidebug_drmmap[] = {
    [WIIPROTO_REQ_NULL] = "NULL",
    [WIIPROTO_REQ_DRM_K] = "K",
    [WIIPROTO_REQ_DRM_KA] = "KA",
    [WIIPROTO_REQ_DRM_KE] = "KE",
    [WIIPROTO_REQ_DRM_KAI] = "KAI",
    [WIIPROTO_REQ_DRM_KEE] = "KEE",
    [WIIPROTO_REQ_DRM_KAE] = "KAE",
    [WIIPROTO_REQ_DRM_KIE] = "KIE",
    [WIIPROTO_REQ_DRM_KAIE] = "KAIE",
    [WIIPROTO_REQ_DRM_E] = "E",
    [WIIPROTO_REQ_DRM_SKAI1] = "SKAI1",
    [WIIPROTO_REQ_DRM_SKAI2] = "SKAI2",
    [WIIPROTO_REQ_MAX] = NULL
};

static int wiidebug_drm_show(struct seq_file *f, void *p)
{
    struct wiimote_debug *dbg = f->private;
    const char *str = NULL;
    unsigned long flags;
    __u8 drm;

    spin_lock_irqsave(&dbg->wdata->state.lock, flags);
    drm = dbg->wdata->state.drm;
    spin_unlock_irqrestore(&dbg->wdata->state.lock, flags);

    if (drm < WIIPROTO_REQ_MAX)
        str = wiidebug_drmmap[drm];
    if (!str)
        str = "unknown";

    seq_printf(f, "%s\n", str);

    return 0;
}

static int wiidebug_drm_open(struct inode *i, struct file *f)
{
    return single_open(f, wiidebug_drm_show, i->i_private);
}

static ssize_t wiidebug_drm_write(struct file *f, const char __user *u,
                            size_t s, loff_t *off)
{
    struct wiimote_debug *dbg = f->private_data;
    unsigned long flags;
    char buf[16];
    ssize_t len;
    int i;

    if (s == 0)
        return -EINVAL;

    len = min((size_t) 15, s);
    if (copy_from_user(buf, u, len))
        return -EFAULT;

    buf[15] = 0;

    for (i = 0; i < WIIPROTO_REQ_MAX; ++i) {
        if (!wiidebug_drmmap[i])
            continue;
        if (!strcasecmp(buf, wiidebug_drmmap[i]))
            break;
    }

    if (i == WIIPROTO_REQ_MAX)
        i = simple_strtoul(buf, NULL, 10);

    spin_lock_irqsave(&dbg->wdata->state.lock, flags);
    wiiproto_req_drm(dbg->wdata, (__u8) i);
    spin_unlock_irqrestore(&dbg->wdata->state.lock, flags);

    return len;
}

static const struct file_operations wiidebug_drm_fops = {
    .owner = THIS_MODULE,
    .open = wiidebug_drm_open,
    .read = seq_read,
    .llseek = seq_lseek,
    .write = wiidebug_drm_write,
    .release = single_release,
};

int wiidebug_init(struct wiimote_data *wdata)
{
    struct wiimote_debug *dbg;
    unsigned long flags;
    int ret = -ENOMEM;

    dbg = kzalloc(sizeof(*dbg), GFP_KERNEL);
    if (!dbg)
        return -ENOMEM;

    dbg->wdata = wdata;

    dbg->eeprom = debugfs_create_file("eeprom", S_IRUSR,
        dbg->wdata->hdev->debug_dir, dbg, &wiidebug_eeprom_fops);
    if (!dbg->eeprom)
        goto err;

    dbg->drm = debugfs_create_file("drm", S_IRUSR,
            dbg->wdata->hdev->debug_dir, dbg, &wiidebug_drm_fops);
    if (!dbg->drm)
        goto err_drm;

    spin_lock_irqsave(&wdata->state.lock, flags);
    wdata->debug = dbg;
    spin_unlock_irqrestore(&wdata->state.lock, flags);

    return 0;

err_drm:
    debugfs_remove(dbg->eeprom);
err:
    kfree(dbg);
    return ret;
}

void wiidebug_deinit(struct wiimote_data *wdata)
{
    struct wiimote_debug *dbg = wdata->debug;
    unsigned long flags;

    if (!dbg)
        return;

    spin_lock_irqsave(&wdata->state.lock, flags);
    wdata->debug = NULL;
    spin_unlock_irqrestore(&wdata->state.lock, flags);

    debugfs_remove(dbg->drm);
    debugfs_remove(dbg->eeprom);
    kfree(dbg);
}